Electric storage element and method for manufacturing electric storage element

ABSTRACT

An electric storage element includes an electrode body including a positive electrode and a negative electrode, the electrode body including a coated region, which includes active materials applied to surfaces of the positive electrode and the negative electrode, and a non-coated region not including the active material on the surface of the positive electrode or the negative electrode, a case including a case body for housing the electrode body and a lid plate that covers an opening of the case body, the case body including a bottom wall having a long side and a short side, the case body further including a side wall standing on the short side of the bottom wall, the lid plate being formed with an electrode terminal, and an insulating member arranged in the case to insulate the electrode body from the case.

The present application is a Continuation Application of U.S. patentapplication Ser. No. 13/765,405, filed on Feb. 12, 2013, which is basedon and claims priority from Japanese Patent Application No. 2012-030821,filed on Feb. 15, 2012, and Japanese Patent Application No. 2013-004871,filed on Jan. 15, 2013, the entire contents of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electric storage element providedwith an electrode body having a positive electrode and a negativeelectrode, an insulating member for insulating the electrode body from acase, and a spacer arranged in the case, and a method for manufacturingthe electric storage element.

2. Description of the Related Art

As an approach to global environmental issues, it becomes increasinglyimportant to convert a gasoline car to an electric car. Thus, anelectric car having an electric storage element such as a lithium-ionsecondary battery as its power source has been developed.

An electric storage element houses an electrode body having a positiveelectrode and a negative electrode in a case. Because of a space betweenthe electrode body and the case, extra electrolyte solution may beneeded. The space may cause a swing or vibration of the electrode bodyin the case. Conventionally, a battery has been proposed in which aspacer is provided between the electrode body and the case so that thespace between the electrode body and the case can be reduced (forexample, refer to JP-A-2006-40899).

However, according to the conventional electric storage element, it isnecessary to insert the spacer into the case in addition to theelectrode body when the electric storage element is manufactured, whichcomplicates a step of inserting them into the case. In addition, afterthe spacer has been inserted into the case, the spacer could be shiftedin position in the case.

SUMMARY OF THE INVENTION

An aspect of the present invention provides an electric storage elementincluding an electrode body having a positive electrode and a negativeelectrode, a case for housing the electrode body, an insulating memberarranged in the case to insulate the electrode body from the case, and aspacer arranged in the case, wherein the spacer is arranged between theinsulating member and the electrode body.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the invention will become apparentto one skilled in the art to which the present invention relates uponconsideration of the invention with reference to the accompanyingdrawings, wherein:

FIG. 1 is a perspective view schematically showing an outer appearanceof an electric storage element according to an embodiment of the presentinvention;

FIG. 2 is an exploded perspective view of the electric storage elementother than a case according to the embodiment of the present invention;

FIG. 3 is a view showing that a bottom spacer and an electrode body areto be inserted into the case under the condition that they are coveredwith an insulating member according to the embodiment of the presentinvention;

FIG. 4 is a view showing a positional relationship between the electrodebody and the bottom spacer in the electric storage element according tothe embodiment of the present invention;

FIG. 5A is a view showing a configuration of the bottom spacer accordingto the embodiment of the present invention;

FIG. 5B is a view showing a configuration of the bottom spacer accordingto the embodiment of the present invention;

FIG. 6 is a flowchart showing one example of a method for manufacturingthe electric storage element according to the embodiment of the presentinvention;

FIG. 7A is a view describing the method for manufacturing the electricstorage element according to the embodiment of the present invention;

FIG. 7B is a view describing the method for manufacturing the electricstorage element according to the embodiment of the present invention;

FIG. 7C is a view describing the method for manufacturing the electricstorage element according to the embodiment of the present invention;

FIG. 8 is a view showing a configuration of an electric storage elementaccording to a variation 1 of the embodiment of the present invention;

FIG. 9 is a view showing a configuration of an electric storage elementaccording to a variation 2 of the embodiment of the present invention;

FIG. 10 is a view showing a configuration of an electric storage elementaccording to the variation 2 of the embodiment of the present invention;

FIG. 11 is a view showing a configuration of the electric storageelement according to the variation 2 of the embodiment of the presentinvention;

FIG. 12 is a view showing a configuration of a bottom spacer in anelectric storage element according to a variation 3 of the embodiment ofthe present invention;

FIG. 13A is a view describing a bottom spacer in an electric storageelement according to a variation 4 of the embodiment of the presentinvention;

FIG. 13B is a view describing the bottom spacer in the electric storageelement according to the variation 4 of the embodiment of the presentinvention;

FIG. 13C is a view describing the bottom spacer in the electric storageelement according to the variation 4 of the embodiment of the presentinvention; and

FIG. 14 is a view describing a spacer in an electric storage elementaccording to a variation 5 of the embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As described above, an aspect of the present invention provides anelectric storage element including an electrode body having a positiveelectrode and a negative electrode, a case for housing the electrodebody, an insulating member arranged in the case to insulate theelectrode body from the case, and a spacer arranged in the case, whereinthe spacer is arranged between the insulating member and the electrodebody.

With this configuration, the electric storage element has theconfiguration in which the spacer is arranged between the insulatingmember and the electrode body. That is, the spacer is fixed to theelectrode body under the condition that it is sandwiched between theinsulating member and the electrode body. Thus, the spacer is insertedinto the case under the condition that it is fixed between theinsulating member and the electrode body, whereby the electric storageelement is provided. Thus, since the spacer is inserted into thecase-under the condition that it is fixed to the electrode body with theinsulating member, the spacer can be smoothly inserted into the case,while the spacer is prevented from being shifted in position in thecase.

The spacer may be configured to reduce a space between the electrodebody and the case, and suppress the electrode body from moving in thecase.

With this configuration, the spacer having a relatively large volume isarranged along a bottom surface or a side surface of the case, and fixedto the electrode body under the condition that it is sandwiched betweenthe insulating member and the electrode body. Thus, the spacer isinserted into the case under the condition that a relative positionbetween the electrode body and the spacer is fixed with the insulatingmember. Therefore, even when the spacer is a bottom spacer which isinserted into the case ahead of the electrode body and arranged alongthe bottom surface of the case, the bottom spacer can be prevented frombeing shifted in position in the case.

The insulating member may be arranged to cover the spacer and theelectrode body.

The electric storage element has the configuration in which theinsulating member is arranged so as to cover the electrode body and thespacer. That is, the insulating member wraps around the electrode bodyand the spacer to fix the electrode body and the spacer. Therefore, thespacer is covered with the insulating member, fixed to the electrodebody, and inserted into the case, so that the spacer can be smoothlyinserted into the case, while the spacer is prevented from being shiftedin position in the case.

The insulating member may be a sheet-shaped member.

With this configuration, since the insulating member is the sheet-shapedmember, it can easily wrap around the spacer and fix it to the electrodebody.

The insulating member may be bonded or welded to the spacer.

With this configuration, the spacer can be effectively prevented frombeing shifted in position in the case.

The spacer may have an internal part opposed to the electrode body, andtwo side parts arranged on both sides of the internal part, and at leastone side part of the two side parts and the internal part may beconnected through a curved surface.

With this configuration, at least one side part and the internal part ofthe spacer are connected through the curved surface. That is, the spacerhas a round tip end which comes in contact with the electrode body whenit is fixed to the electrode body. Thus, when the spacer is fixed to theelectrode body, the electrode body is prevented from being damaged withthe tip end of the spacer.

The spacer may have an internal part opposed to the electrode body, twoside parts arranged on both sides of the internal part, and an externalpart arranged between the two side parts and opposed to the insulatingmember, and at least one side part of the two side parts and theexternal part may be connected through a curved surface.

With this configuration, at least one side part and the external part ofthe spacer are connected through the curved surface. That is, the spacerhas a round corner part which comes in contact with the insulatingmember. Thus, even when the spacer and the insulating member are broughtinto contact with each other due to vibration or the like, theinsulating member can be prevented from being damaged with the cornerpart of the spacer.

The spacer may be an insulating member.

With this configuration even when the insulating member is damaged whilethe spacer is wrapped with the insulating member and fixed to theelectrode body, an insulating property can be kept between the electrodebody and the case.

The electrode body may have a coated region having active materialsapplied to surfaces of the positive electrode and the negativeelectrode, and a non-coated region not having the active material on thesurface of the positive electrode or the negative electrode, the spacermay have a first part opposed to the non-coated region, and a secondpart opposed to the coated region, and the first part may be thickerthan the second part.

With this configuration, the first part of the spacer opposed to thenon-coated region of the active material is thicker than the second partof the spacer opposed to the coated region of the active material. Inthe non-coated region, the performance of the electric storage elementis not likely to be degraded even when compression is applied thereto.According to this electric storage element, in order to enhancevibration resistance thereof, the first part of the spacer opposed tothe non-coated region is formed to be thicker than the second part andthus compression is applied to the non-coated region, so that thevibration resistance can be enhanced, while the performance of theelectric storage element is prevented from being degraded. In addition,the coated region is likely to be expanded due to repeatedcharge-discharge, and the performance of the electric storage element islikely to be degraded when it is excessively compressed. Therefore, thesecond part is formed to be thinner than the first part in the spacer,so that there can be provided a space for tolerating the expansion ofthe electrode body, and the performance of the electric storage elementcan be prevented from being degraded even when the electrode body isexpanded.

A clearance between the second part of the spacer and the coated regionof the electrode body may be larger than a clearance between the firstpart of the spacer and the non-coated region of the electrode body.

With this configuration, the spacer is formed in such a manner that theclearance between the spacer and the coated region of the electrode bodyis larger than the clearance between the spacer and the non-coatedregion of the electrode body. Therefore, even when the coated region ofthe electrode body is expanded due to the repeated charge-discharge, theexpansion of the coated region of the electrode body can be toleratedbecause the clearance is large in the coated region. In addition, sincethe clearance is small in the non-coated region of the electrode body inwhich the performance of the electric storage element is not likely tobe degraded due to the compression, the vibration resistance can beimproved while the performance of the electric storage element isprevented from being degraded.

The shape of the first part of the spacer on a side of the electrodebody may follow an outer surface of the electrode body.

With this configuration, since the shape of the first part of the spaceron the side of the electrode body follows the shape of the electrodebody, the clearance can be minimized in the first part. As a result, thevibration resistance can be further improved in the first part of thespacer.

The spacer may have the two first parts arranged at both ends in alongitudinal direction, the two second parts connected to the two firstparts, respectively, and a third part thinner than the two second parts,between the two second parts.

With this configuration, the spacer has the third part thinner than thesecond part, between the two second parts. That is, since the electrodebody can be supported with the first part and the second part of thespacer, the third part provided between the two second parts and notused for supporting the electrode body can be thinned, so that costs canbe reduced due to a reduction in amount of a component material.

Another aspect of the present invention provides a method formanufacturing an electric storage element including an electrode bodyhaving a positive electrode and a negative electrode, a case for housingthe electrode body, an insulating member arranged in the case toinsulate the electrode body from the case, and a spacer arranged in thecase, the method including an arranging step of arranging the spacerbetween the insulating member and the electrode body, and an insertingstep of inserting the spacer into the case together with the insulatingmember and the electrode body.

With this configuration, the spacer is arranged between the insulatingmember and the electrode body. That is, the spacer is fixed to theelectrode body under the condition that it is sandwiched between theinsulating member and the electrode body. Thus, the spacer is insertedinto the case under the condition that it is fixed between theinsulating member and the electrode body, whereby the electric storageelement is provided. Thus, since the spacer is inserted into the caseunder the condition that it is fixed to the electrode body with theinsulating member, the spacer can be smoothly inserted into the case,while the spacer is prevented from being shifted in position in thecase.

In the arranging step, the spacer may be arranged between the insulatingmember and the electrode body such that the spacer and the electrodebody are covered with the insulating member.

With this configuration, the spacer is arranged between the insulatingmember and the electrode body such that the spacer and the electrodebody are covered with the insulating member. That is, the insulatingmember wraps around the electrode body and the spacer to fix theelectrode body and the spacer. Therefore, the spacer is covered with theinsulating member, fixed to the electrode body, and inserted into thecase, so that the spacer can be smoothly inserted into the case, whilethe spacer is prevented from being shifted in position in the case.

In the arranging step, the spacer may be set on the insulating member,the electrode body, which is formed into an oval shape by winding theelongated band-shaped positive electrode and negative electrode around awinding axis, may be put sideways, and the insulating member may bewound around the electrode body such that the spacer is arranged betweenthe insulating member and the electrode body.

With this configuration, manufacturing efficiency can be improved.

Preferred embodiments of the present invention will be described.Hereinafter, a description will be given of an electric storage elementand a method for manufacturing the electric storage element according toan embodiment of the present invention, with reference to the drawings.In addition, each embodiment which will be described below shows onepreferred specific example of the present invention. Numeric values,shapes, materials, components, and arranged positions and connectedconfigurations of the components shown in the following embodiment areillustrative only, and do not limit the present invention.

First, a configuration of an electric storage element 10 will bedescribed.

FIG. 1 is a perspective view schematically showing an outer appearanceof the electric storage element 10 according to an embodiment of thepresent invention. FIG. 2 is an exploded perspective view of theelectric storage element 10 according to the embodiment of the presentinvention other than a case 100. That is, FIG. 2 is a view showingcomponents arranged in the case 100 of the electric storage element 10.

The electric storage element 10 serves as a secondary battery capable ofcharging and discharging electricity and more specifically, serves as anon-aqueous electrolyte battery such as a lithium-ion secondary battery.

As shown in FIGS. 1 and 2, the electric storage element 10 is providedwith the case 100, and a lid plate 110, a positive electrode terminal200, and a negative electrode terminal 300 which are provided in anupper part of the case 100. In addition, the case 100 contains anelectrode body 120, a positive electrode collector 130, a negativeelectrode collector 140, side spacers 150 and 160, a bottom spacer 170,and an insulating member 180.

In addition, a liquid such as an electrolyte solution is encapsulated inthe case 100 of the electric storage element 10, but the liquid is notshown in the drawing. Incidentally, the electric storage element 10 isnot limited to the non-aqueous electrolyte battery, and it may be asecondary battery other than the non-aqueous electrolyte battery, or maybe a capacitor.

The case 100 is a bottomed rectangular cylindrical case body made ofmetal, and an opening of the case body is covered with the metal lidplate 110. That is, the case 100 can be hermetically sealed by beingsoldered with the lid plate 110 after the electrode body 120 and thelike have been housed therein. In this embodiment, the opening of thecase 100 is defined as having a surface opposed to a bottom surface ofthe case 100.

The electrode body 120 is provided with a positive electrode, a negativeelectrode, and a separator although they are not described in detail,and serves as a member capable of storing electricity. The positiveelectrode is provided by forming an active material layer for thepositive electrode on a surface of an elongated band-shaped positiveelectrode base member made of aluminum foil. The negative electrode isprovided by forming an active material layer for the negative electrodeon a surface of an elongated band-shaped negative electrode base membermade of copper foil. The separator is a macro-porous sheet made ofresin. The electrode body 120 is formed in such a manner that the abovecomponents are wound into the form of an oval shape as a whole in layerswith the separator sandwiched between the negative electrode and thepositive electrode.

More specifically, the positive electrode and the negative electrode areshifted in a width direction of the elongated band from each other withthe separator interposed therebetween and wound around a winding axisalong the width direction into the oval shape. Thus, by forming a regionhaving no active material applied, in an edge part of each of thepositive electrode and the negative electrode in their shifteddirection, the aluminum foil of the positive electrode base member onwhich the active material is not formed is exposed to one end of thewinding axis, and the copper foil of the negative electrode base memberon which the active material is not formed is exposed to another end ofthe winding axis. In addition, the positive electrode collector 130 andthe negative electrode collector 140 which extend in a directionvertical to a winding axis direction are arranged in ends of theelectrode body 120 in the winding axis direction, respectively.

In addition, the electrode body 120 has a flat part in which thepositive electrode, the negative electrode, and the separator arelaminated in a flat surface, and a curved part in which they arelaminated in a curved surface. Thus, the electrode body 120 is housed inthe case 100 in such a manner that the curved part is opposed to thebottom surface of the case 100.

Here, the active material for the positive electrode includes apolyanion compound such as LiMPO₄, LiMSiO₄, or LiMBO₃ (M is one or morekinds of transition metal elements selected from Fe, Ni, Mn, Co, and thelike), a spinel compound such as lithium titanate or lithium manganite,and a lithium transition metal oxide such as LiMO₂ (M is one or morekinds of transition metal elements selected from Fe, Ni, Mn, Co, and thelike).

In addition, the active material for negative electrode may be awell-known material as long as the material can absorb and emit lithiumions. For example, the material includes lithium metal, lithium alloy(alloy containing lithium metal such as lithium-silicon,lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin,lithium-gallium, or wood's alloy) as well as an alloy capable ofabsorbing and emitting lithium, a carbon material (such as black lead,non-graphitizable carbon, graphitizable carbon, low-temperature firedcarbon, or amorphous carbon), silicon oxide, metal oxide, lithium metaloxide (such as Li₄Ti₅O₁₂), and polyphosphate compound.

The oval shape is shown as the shape of the electrode body 120 in FIG.2, but the shape may be a circular shape or ellipsoidal shape.

The positive electrode terminal 200 serves as an electrode terminalelectrically connected to the positive electrode of the electrode body120, and the negative electrode terminal 300 serves as an electrodeterminal electrically connected to the negative electrode of theelectrode body 120. That is, each of the positive electrode terminal 200and the negative electrode terminal 300 serves as the metal electrodeterminal which discharges electricity stored in the electrode body 120to an external space of the electric storage element 10, and introduceselectricity into the internal space of the electric storage element 10in order to store electricity in the electrode body 120. In addition,the positive electrode terminal 200 and the negative electrode terminal300 are mounted on the lid plate 110 arranged in the upper part of theelectrode body 120.

The positive electrode collector 130 is arranged between the positiveelectrode of the electrode body 120 and a side wall of the case 100, andit is a conductive and rigid member electrically connected to thepositive electrode terminal 200 and the positive electrode of theelectrode body 120. The positive electrode collector 130 is made ofaluminum, similar to the positive electrode of the electrode body 120.

The negative electrode collector 140 is arranged between the negativeelectrode of the electrode body 120 and a side wall of the case 100, andit is a conductive and rigid member electrically connected to thenegative electrode terminal 300 and the negative electrode of theelectrode body 120. The negative electrode collector 140 is made ofcopper, similar to the negative electrode of the electrode body 120.

The side spacers 150 and 160 are arranged between the positive electrodecollector 130 and the side wall of the case 100, and between thenegative electrode collector 140 and the side wall of the case 100,respectively, and serve as elongated insulating members extending alongthe positive electrode collector 130 and the negative electrodecollector 140, respectively. For example, the side spacers 150 and 160are made of resin such as polypropylene (PP). That is, the side spacers150 and 160 insulate the positive electrode collector 130 and thenegative electrode collector 140 from the case 100, respectively.Furthermore, the side spacers 150 and 160 fill a space between thepositive electrode collector 130 and the case 100 and a space betweenthe negative electrode collector 140 and the case 100, respectively, sothat the electrode body 120 is prevented from vibrating with the case100 via the positive electrode collector 130 and the negative electrodecollector 140.

The bottom spacer 170 is arranged between the electrode body 120 and thebottom surface of the case 100 and serves as an elongated insulatingmember extending along the winding axis direction of the electrode body120. For example, the bottom spacer 170 is made of resin such aspolypropylene (PP). More specifically, the bottom spacer 170 is arrangedbetween the bottom surface of the case 100 and the curved part of theelectrode body 120. That is, the bottom spacer 170 insulates theelectrode body 120 from the case 100. Furthermore, the bottom spacer 170fills a space between the electrode body 120 and the case 100, so thatthe electrode body 120 is prevented from vibrating with the case 100. Aconfiguration of the bottom spacer 170 will be described in detaillater.

An insulating member 180 insulates the electrode body 120 from the case100. More specifically, the insulating member 180 is a sheet-shapedinsulating member, and arranged so as to cover the bottom spacer 170 andthe electrode body 120. That is, the insulating member 180 is shapedlike an exploded bag, and wraps around the bottom spacer 170, the sidespacers 150 and 160, the positive electrode collector 130, the negativeelectrode collector 140, and a side surface of the electrode body 120,from beneath the bottom spacer 170. Thus, the bottom spacer 170, and theside spacers 150 and 160 are arranged between the insulating member 180and the electrode body 120.

Thus, when the insulating member 180 is formed, its size is adjusted soas to wrap around the bottom spacer 170, the side spacers 150 and 160,and the electrode body 120. Incidentally, the insulating member 180 maynot necessarily wrap around the whole of the electrode body 120, but maybe formed so as to only cover part of the electrode body 120.Incidentally, the insulating member 180 may have any shape as long as itcan be formed into the bag shape.

FIG. 3 is a view showing that the bottom spacer 170 and the electrodebody 120 covered with the insulating member 180 are to be inserted intothe case 100 according to the embodiment of the present invention.

As shown in FIG. 3, the insulating member 180 covers the bottom spacer170, the side spacers 150 and 160, the positive electrode collector 130,the negative electrode collector 140, and the electrode body 120 so asto wrap around them from beneath the bottom spacer 170. Thus, acomponent group covered with the insulating member 180 is inserted intothe case 100.

Next, the configuration of the bottom spacer 170 will be described indetail.

FIG. 4 is a view showing a positional relationship between the electrodebody 120 and the bottom spacer 170 in the electric storage element 10according to the embodiment of the present invention. In FIG. 4, thepositive electrode collector 130, the negative electrode collector 140,the side spacers 150 and 160, and the insulating member 180 are notshown.

FIGS. 5A and 5B are views showing the configuration of the bottom spacer170 according to the embodiment of the present invention. Morespecifically, FIG. 5A is an oblique perspective view of an outerappearance of the bottom spacer 170, and FIG. 5B is a view of the bottomspacer 170 taken from lower left in FIG. 5A.

First, as shown in FIG. 4, a non-coated region A1 in which the activematerial is not applied to the positive electrode or the negativeelectrode is provided in each end of the electrode body 120 in thewinding axis direction, and a-coated region A2 in which the activematerial is applied to each of the positive electrode and the negativeelectrode is provided between the non-coated regions A1 in the center ofthe electrode body 120 in the winding axis direction.

Thus, the bottom spacer 170 has two first parts 171 opposed to thenon-coated regions A1 of the electrode body 120, and a second part 172opposed to the coated region A2 of the electrode body 120. As for thebottom spacer 170, a cross-sectional shape of the first part 171 isdifferent from a cross-sectional shape of the second part 172 whenviewed from a plane perpendicular to the winding axis direction of theelectrode body 120.

More specifically, as shown in FIGS. 5A and 5B, the first part 171 isformed to be thicker than the second part 172. That is, a clearancebetween the second part 172 of the bottom spacer 170 and the coatedregion A2 of the electrode body 120 is larger than a clearance betweenthe first part 171 of the bottom spacer 170 and the non-coated region A1of the electrode body 120.

In addition, the first part 171 has an internal part 171 a, two sideparts 171 b, and an external part 171 c.

The internal part 171 a is opposed to the electrode body 120 and has ashape along an outer surface of the electrode body 120. That is, a shapeof the first part 171 of the bottom spacer 170 on the side of theelectrode body 120 follows an outer surface of the non-coated region A1of the electrode body 120. More specifically, the internal part 171 ahas a dented curved shape.

The side part 171 b has a flat surface provided on each side of theinternal part 171 a. That is, a side shape of the first part 171 of thebottom spacer 170 follows an internal side surface of the case 100.

The external part 171 c is a flat surface arranged between the two sideparts 171 b so as to be opposed to the insulating member 180. That is, abottom shape of the first part 171 of the bottom spacer 170 follows aninternal bottom surface of the case 100.

Thus, at least one side part 171 b of the two side parts 171 b and theinternal part 171 a are connected through a curved surface. That is, asshown in FIG. 5B, the two side parts 171 b and the internal part 171 aare connected through curved surfaces R1 and R2, respectively.Incidentally, the curved surfaces R1 and R2 may have any shape as longas they are curved, and for example, each of them may have an arc shapedcross-section having a radius of 1 mm to 2 mm.

In addition, at least one side part 171 b of the two side parts 171 band the external part 171 c are connected through a curved surface. Thatis, as shown in FIG. 5B, the two side parts 171 b and the external part171 c are connected through curved surfaces R3 and R4, respectively.Incidentally, the curved surfaces R3 and R4 may have any shape as longas they are curved, and for example, each of them may have an arc shapedcross-section having a radius of 1 mm to 3 mm.

Similar to the first part 171, the second part 172 has an internal part172 a, two side parts 172 b, and an external part 172 c.

The internal part 172 a is opposed to the electrode body 120 and has ashape along an outer surface of the electrode body 120. That is, a shapeof the second part 172 of the bottom spacer 170 on the side of theelectrode body 120 follows an outer surface of the coated region A2 ofthe electrode body 120. More specifically, the internal part 172 a has adented curved shape.

The side part 172 b is provided on each side of the internal part 172 a.That is, a side shape of the second part 172 of the bottom spacer 170follows an internal side surface of the case 100.

The external part 172 c is a surface arranged between the two side parts172 b so as to be opposed to the insulating member 180. That is, abottom shape of the second part 172 of the bottom spacer 170 follows aninternal bottom surface of the case 100.

Thus, similar to the first part 171, at least one side part 172 b of thetwo side parts 172 b and the internal part 172 a are connected through acurved surface. Here, both of the two side parts 172 b and the internalpart 172 a are connected through the curved surfaces. Incidentally, thecurved surface may have any shape as long as it is curved, and forexample, it may have an arc shaped cross-section having a radius of 1 mmto 2 mm.

In addition, similar to the first part 171, at least one side part 172 bof the two side parts 172 b and the external part 172 c are connectedthrough a curved surface. Here, both of the two side parts 172 b and theexternal part 171 c are connected through the curved surfaces.Incidentally, the curved surface may have any shape as long as it iscurved, and for example, it may have an arc shaped cross-section havinga radius of 1 mm to 3 mm.

As described above, as for the bottom spacer 170, the curved surface isprovided at each end of the bottom spacer 170 in a width direction, ateach tip end of the side part arranged so as to extend in a longitudinaldirection of the bottom spacer 170 along the side of the electrode body120.

In addition, similar to the first part 171 and the second part 172, aninternal part of each of the side spacers 150 and 160 opposed to theelectrode body 120, and two side parts arranged on both sides of theinternal part thereof may be connected though curved surfaces. Inaddition, the two side parts of each of the side spacers 150 and 160 andan external part arranged between the two side parts so as to be opposedto the insulating member 180 may be connected through curved surfaces.

As described above, according to the electric storage element 10 in theembodiment of the present invention, the bottom spacer 170 is arrangedbetween the insulating member 180 and the electrode body 120. That is,the bottom spacer 170 having a relatively large volume which is arrangedalong the bottom surface of the case 100, is fixed to the electrode body120 under the condition that it is sandwiched between the insulatingmember 180 and the electrode body 120. Thus, the bottom spacer 170 isinserted into the case 100 under the condition that it is fixed betweenthe insulating member 180 and the electrode body 120 (that is, under thecondition that a relative position between the electrode body 120 andthe bottom spacer 170 is fixed with the insulating member 180), wherebythe electric storage element 10 is provided. Thus, the bottom spacer 170is inserted into the case 100 ahead of the electrode body 120 and pushedby the electrode body 120 toward the bottom of the case 100 under thecondition that it is fixed to the electrode body 120 with the insulatingmember 180, so that the bottom spacer 170 can be smoothly inserted intothe case 100, while the bottom spacer 170 is prevented from beingshifted in position in the case 100.

In addition, the electric storage element 10 has the configuration inwhich the insulating member 180 is arranged so as to cover the electrodebody 120 and the bottom spacer 170. That is, the insulating member 180fixes the electrode body 120 and the bottom spacer 170 while wrappingaround the electrode body 120 and the bottom spacer 170. Therefore, thebottom spacer 170 is inserted into the case 100 while it is covered withthe insulating member 180 and fixed to the electrode body 120, so thatthe bottom spacer 170 can be smoothly inserted into the case 100,while-the bottom spacer 170 is prevented from being shifted in positionin the case 100.

In addition, since the insulating member 180 is the sheet-shaped member,it can wrap around the bottom spacer 170 and fix it to the electrodebody 120 with ease.

Furthermore, at least one side part and the internal part of the bottomspacer 170 are connected through the curved surface. That is, the bottomspacer 170 has the round tip end which comes in contact with theelectrode body 120 when it is fixed to the electrode body 120. Thus,when the bottom spacer 170 is fixed to the electrode body 120, theelectrode body 120 can be prevented from being damaged with the tip endof the bottom spacer 170.

Furthermore, at least one side part and the external part of the bottomspacer 170 are connected through the curved surface. That is, the bottomspacer 170 has the round corner part which comes in contact with theinsulating member 180. Thus, even when the bottom spacer 170 and theinsulating member 180 come in contact with each other due to vibration,the insulating member 180 can be prevented from being damaged with thecorner part of the bottom spacer 170.

In addition, the bottom spacer 170 is the insulating member, so thateven in a case where the insulating member 180 is damaged when thebottom spacer 170 is wrapped with the insulating member 180 and fixed tothe electrode body 120, insulating properties between the electrode body120 and the case 100 can be ensured.

Still furthermore, the first part 171 of the bottom spacer 170 opposedto the non-coated region A1 of the active-material is thicker than thesecond part 172 of the bottom spacer 170 opposed to the coated region A2of the active material. Here, it is to be noted that the non-coatedregion A1 is a region in which performance of the electric storageelement 10 is not likely to be degraded even when compression is appliedthereto. As for the electric storage element 10, in order to enhance itsvibration resistance, the first part 171 opposed to the non-coatedregion A1 is formed to be thicker than the second part 172 in the bottomspacer 170 and compression is applied to the non-coated region A1, sothat the vibration resistance can be enhanced while the performance ofthe electric storage element 10 is prevented from being degraded. Inaddition, the coated region A2 is likely to be expanded due to repeatedcharge-discharge, so that when compression is excessively appliedthereto, the performance of the electric storage element 10 is likely tobe degraded. Therefore, since the second part 172 is formed to bethinner than the first part 171 in the bottom spacer 170, a space fortolerating the expansion of the electrode body 120 can be provided, sothat even when the electrode body 120 is expanded, the performance ofthe electric storage element 10 can be prevented from being degraded.

In addition, the clearance between the bottom spacer 170 and the coatedregion A2 of the electrode body 120 is larger than the clearance betweenthe bottom spacer 170 and the non-coated region A2 of the electrode body120. Therefore, even when the coated region A2 of the electrode body 120is expanded due to the repeated charge-discharge, the expansion of thecoated region A2 of the electrode body 120 can be tolerated because theclearance is large in the coated region A2. In addition, the electrodebody 120 has the small clearance in the non-coated region A1 in whichdegradation in performance of the electric storage element 10 is notlikely to be caused by the compression, so that the vibration resistancecan be improved, while the performance of the electric storage element10 is not degraded.

Since the shape of the first part 171 of the bottom spacer 170 on theside of the electrode body 120 follows the shape of the electrode body120, the clearance can be minimized in the first part 171. As a result,the vibration resistance in the first part 171 can be further improvedin the bottom spacer 170.

Next, a method for manufacturing the electric storage element 10 will bedescribed.

FIG. 6 is a flowchart showing one example of the method formanufacturing the electric storage element 10 according to theembodiment of the present invention.

FIGS. 7A to 7C are views describing the method for manufacturing theelectric storage element 10 according to the embodiment of the presentinvention. In FIGS. 7A to 7C, the lid plate 110, the positive electrodecollector 130, the negative electrode collector 140, and the sidespacers 150 and 160 are not shown.

First, as shown in FIG. 6, in a step of arranging the bottom spacer 170,the bottom spacer 170 is arranged between the insulating member 180 andthe electrode body 120 (S102).

More specifically, as shown in FIG. 7A, the bottom spacer 170 is set onthe insulating member 180, and attached thereto (fixed with a bondingagent or a bonding tape). Alternatively, ultrasonic welding may be used.In addition, the electrode body 120 is set sideways on the insulatingmember 180 adjacent to the bottom spacer 170, with its bottom opposed tothe bottom spacer 170.

Then, as shown in FIG. 7B, the insulating member 180 is lifted togetherwith the bottom spacer 170 so as to be wound around the electrode body120. At this time, the tip end of the bottom spacer 170 abuts on theelectrode body 120 as shown in FIG. 7B, but the electrode body 120 canbe prevented from being damaged because the tip end of the bottom spacer170 is rounded.

Then, as shown in FIG. 7C, the insulating member 180 is wound around theelectrode body 120 so that the bottom spacer 170 and the electrode body120 are covered with the insulating member 180. As a result, the bottomspacer 170 is arranged between the insulating member 180 and theelectrode body 120.

Thus, referring to FIG. 6 again, in a step of inserting the bottomspacer 170, the bottom spacer 170 is inserted into the case 100 togetherwith the insulating member 180 and the electrode body 120 (S104).

More specifically, as shown in FIG. 7C, the case 100 is arrangedsideways so that its opening faces to a horizontal direction. Thus, thecomponent group having the bottom spacer 170 and the electrode body 120wrapped with the insulating member 180 is horizontally inserted into thecase 100 through the opening of the case 100.

Thus, since the case 100 is arranged sideways, the case 100 can beeasily held by strong force, and the component group having the bottomspacer 170 and the electrode-body 120 wrapped with the insulating member180 can be easily inserted into the case 100.

As described above, according to the method for manufacturing theelectric storage element 10 in the embodiment of the present invention,the bottom spacer 170 is disposed between the insulating member 180 andthe electrode body 120. That is, the bottom spacer 170 is fixed to theelectrode body 120 under the condition that it is sandwiched between theinsulating member 180 and the electrode body 120. Thus, the bottomspacer 170 is inserted into the case 100 under the condition that it isfixed between the insulating member 180 and the electrode body 120,whereby the electric storage element 10 is provided. In this way, sincethe bottom spacer 170 is inserted into the case 100 under the conditionthat it is fixed to the electrode body 120 with the insulating member180, the bottom spacer 170 can be smoothly inserted into the case 100,while the bottom spacer 170 is prevented from being shifted in positionin the case 100.

In addition, the bottom spacer 170 is arranged between the insulatingmember 180 and the electrode body 120 such that the electrode body 120and the bottom spacer 170 are covered with the insulating member 180.That is, the electrode body 120 and the bottom spacer 170 are fixed insuch a manner that the insulating member 180 wraps around the electrodebody 120 and the bottom spacer 170. Therefore, since the bottom spacer170 is inserted into the case 100 under the condition that it is coveredwith the insulating member 180 and fixed to the electrode body 120, thebottom spacer 170 can be smoothly inserted into the case 100, while thebottom spacer 170 is prevented from being shifted in position in thecase 100.

(Variation 1)

Next, a variation 1 of this embodiment will be described. According tothe above embodiment, the insulating member 180 is the sheet-shapedmember. However, according to this variation 1, the insulating member isa bag-shaped member.

FIG. 8 is a view showing a configuration of an electric storage element11 according to the variation 1 of the embodiment of the presentinvention. In FIG. 8, a configuration in the case 100 is shown, whilethe case 100 is not shown.

As shown in FIG. 8, the electric storage element 11 is provided with abag-shaped insulating member 181 having an opening in its upper part.The insulating member 181 is an insulating member provided by forming aninsulating sheet into a bag shape.

The insulating member 181 is arranged so as to cover the bottom spacer170 and the electrode body 120. That is, the electrode body 120, thepositive electrode collector 130, the negative electrode collector 140,the side spacers 150 and 160, and the bottom spacer 170 are housed inthe insulating member 181, and then inserted into the case 100.

When the insulating member 181 is formed, its size is adjusted so as tobe able to house the electrode body 120, the positive electrodecollector 130, the negative electrode collector 140, the side spacers150 and 160, and the bottom spacer 170 therein. In addition, theinsulating member 181 may not have to entirely house the electrode body120, and it may be formed so as to only cover part of a lower part ofthe electrode body 120.

As described above, according to the electric storage element 11 in thevariation 1 of the embodiment of the present invention, the bag-shapedinsulating member 181 is arranged so as to cover the electrode body 120and the spacers (side spacers 150 and 160 and the bottom spacer 170).That is, the insulating member 181 wraps around the electrode body 120and the spacers, and fixes the electrode body 120 and the spacers.Therefore, since the spacers are inserted into the case 100 under thecondition that they are wrapped with the insulating member 181 and fixedto the electrode body 120, the spacers can be smoothly inserted into thecase 100, while the spacers are prevented from being shifted in positionin the case 100.

(Variation 2)

Next, a variation 2 of this embodiment will be described. According tothe above embodiment, the insulating member 180 covers both of thebottom spacer 170 and the side spacers 150 and 160. However, accordingto this variation 2, the insulating member is arranged so as to coverthe bottom spacer 170 and/or the side spacers 150 and 160.

FIGS. 9 to 11 are views each showing a configuration of an electricstorage element according to the variation 2 of the embodiment of thepresent invention. In FIGS. 9 and 10, a configuration in the case 100 isshown, while the case 100 is not shown.

As shown in FIG. 9, an electric storage element 12 is provided with arectangular sheet-shaped insulating member 182. Thus, the insulatingmember 182 is arranged so as to cover the bottom spacer 170 and theelectrode body 120. That is, the electrode body 120, the positiveelectrode collector 130, the negative electrode collector 140, the sidespacers 150 and 160, and the bottom spacer 170 are covered so as to bewrapped with the insulating member 182 from beneath the electrode body120.

When the insulating member 182 is formed, its size is adjusted so as towrap around the electrode body 120, the positive electrode collector130, the negative electrode collector 140, the side spacers 150 and 160,and the bottom spacer 170. The component group may be provided in such amanner that the side spacers 150 and 160 are mounted on the electrodebody 120, the electrode body 120 and the side spacers 150 and 160 arewrapped with the insulating member 182 bonded or ultrasonically weldedto the spacer 170, and the insulating member 182 is thermally welded tothe side spacers 150 and 160. In addition, the insulating member 182does not have to wrap around the entire electrode body 120, but it maycover only part of the electrode body 120.

In addition, as shown in FIG. 10, an electric storage element 13 isprovided with a rectangular sheet-shaped insulating member 183. Theinsulating member 183 is arranged so as to cover the side spacers 150and 160, and the electrode body 120. That is, the electrode body 120,the positive electrode collector 130, the negative electrode collector140, the side spacers 150 and 160, and the bottom spacer 170 are coveredand wrapped with the insulating member 183 from the side of theelectrode body 120.

Thus, as shown in FIG. 11, an end of the insulating member 183 is fixedwith an adhesive tape 184, and inserted into the case 100.

When the insulating member 183 is formed, its size is-adjusted so as towrap around the electrode body 120, the positive electrode collector130, the negative electrode collector 140, the side spacers 150 and 160,and the bottom spacer 170. In addition, the insulating member 183 doesnot have to wrap around the-entire electrode body 120, but it may coveronly part of the electrode body 120.

As for the configuration of the electric storage element 13, it ispreferable that in order to prevent the electrode body 120 and theinsulating member 183 from being damaged, corner parts of the sidespacers 150 and 160 which come in contact with the electrode body 120 orthe insulating member 183 are curved, similar to the bottom spacer 170.That is, an internal part of each of the side spacers 150 and 160opposed to the electrode body 120, and two side parts arranged on bothsides of the internal part are preferably connected through curvedsurfaces. It is preferable that the two side parts of each of the sidespacers 150 and 160 and an external part arranged between the two sideparts provided opposed to the insulating member 183 are connectedthrough curved surfaces.

As described above, according to the electric storage elements 12 and 13in the variation 2 of the embodiment of the present invention, theinsulating members 182 and 183 are arranged so as to cover the electrodebody 120 and the spacers (side spacers 150 and 160 and bottom spacer170) from beneath and from the side, respectively. That is, each of theinsulating members 182 and 183 fixes the electrode body 120 and thespacers by wrapping the electrode body 120 and the spacers from beneathor from the side. Therefore, the spacers are covered with each of theinsulating members 182 and 183 from beneath or from the side and fixedto the electrode body 120, and then inserted into the case 100, so thatthe spacers can be smoothly inserted into the case 100, while thespacers are prevented from being shifted in position in the case 100.

(Variation 3)

Next, a variation 3 of this embodiment will be described. According tothe above embodiment, the bottom spacer 170 is composed of the two firstparts 171, and the second part 172 sandwiched between the two firstparts 171. However, according to this variation 3, the bottom spacer 170further includes a third part.

FIG. 12 is a view showing a configuration of a bottom spacer 170A of anelectric storage element according to the variation 3 of the embodimentof the present invention.

As shown in FIG. 12, the bottom spacer 170A has the two first parts 171arranged in both ends in a longitudinal direction, and two second parts173 connected to the two first parts 171, respectively. IR addition, thebottom spacer 170A has a third part 174 between the two second parts173.

The third part 174 is a flat portion thinner than the two second parts173. That is, the bottom spacer 170A has a configuration provided byforming a thinner center part in the center of the bottom spacer 170 inthe above embodiment.

Incidentally, the shape of the third part 174 is not limited to the flatshape, and may be any shape such as a curved shape. Furthermore, thefirst part 171, the second part 173, and the third part 174 may be madeof the same material, or may be made of different materials.

As described above, the bottom spacer 170A of the electric storageelement according to the variation 3 of the embodiment of the presentinvention has the third part 174 thinner than the second part 173,between the two second parts 173. That is, the electrode body 120 can besupported with the first parts 171 and the second parts 173 of thebottom spacer 170A, so that the third part 174 which is not used forsupporting the electrode body 120 can be thinned, and costs can bereduced due to a reduction in amount of a component material.

(Variation 4)

Next, a variation 4 of this embodiment will be described. According tothe above embodiment and its variations, the side part and the externalpart of the first part, and the side part and the external part of thesecond part in the bottom spacer have the flat shape, but according tothis variation 4, each of a side part and an external part of a bottomspacer has a curved shape.

FIGS. 13A to FIG. 13C are views each describing a bottom spacer 170B ofan electric storage element according to the variation 4 of theembodiment of the present invention. More specifically, FIG. 13A is aview corresponding to the bottom spacer 170 in FIG. 5B, and FIGS. 13Band 13C are views corresponding to the method for manufacturing theelectric storage element 10 in FIGS. 7A and 7B, respectively.

As shown in FIG. 13A, the bottom spacer 170B is provided with a firstpart 175 and a second part 176. The first part 175 has an internal part175 a as an upper surface, two side parts 175 b as side surfaces, and anexternal part 175 c as a bottom surface. Similarly, the second part 176has an internal part 176 a as an upper surface, two side parts 176 b asside surfaces, and an external part 176 c as a bottom surface.

Each of the two side parts 175 b, the external part 175 c, the two sideparts 176 b, and the external part 176 c has a curved shape. That is,the side part 175 b has a curved surface arranged on each side of theinternal part 175 a, and the external part 175 c has a curved surfacearranged between the two side parts 175 b and opposed to the insulatingmember 180. Furthermore, the side part 176 b has a curved surfacearranged on each side of the internal part 176 a, and the external part176 c has a curved surface arranged between the two side parts 176 b andopposed to the insulating member 180.

Thus, according to processes for manufacturing the electric storageelement having the above bottom spacer 170B, as shown in FIG. 13B, thebottom spacer 170B is put on the insulating member 180 adjacent to theelectrode body 120, and as shown in FIG. 13C, the insulating member 180is lifted together with the bottom spacer 170B so as to be wound aroundthe electrode body 120, so that the insulating member 180 is woundaround the electrode body 120.

At this time, since each of the side part and the external part of thebottom spacer 170B has the curved surface, the insulating member 180 canbe smoothly bent. Thus, the bottom spacer 170B is inserted into the case100 together with insulating member 180 and the electrode body 120.

Incidentally, the side part and the external part of the bottom spacer170B need not entirely have the curved shape, but the curved shape maybe partially provided in one part of the two side parts 175 b, theexternal part 175 c, the two side parts 176 b, and the external part 176c.

(Variation 5)

Next, a variation 5 of this embodiment will be described. According tothe above embodiment and its variations, the side spacer and the bottomspacer are separately provided. However, according to this variation 5,a spacer has a side part functioning as a side spacer, and a bottom partfunctioning as a bottom spacer.

As shown in FIG. 14, a spacer 165 of an electric storage elementaccording to the variation 5 has a side part 165 a and a bottom part 165b. A configuration of this electric storage element other than thisspacer is similar to the electric storage element shown in FIG. 9. Theside part 165 a is arranged along a side wall of a case. The bottom part165 b is arranged along a bottom surface of the case. The side part 165a extends in a direction roughly perpendicular to the bottom part 165 b.The spacer 165 is mounted on the electrode body 120 shown in FIG. 9, andthen the bottom part 165 b is wrapped with the insulating member 182together with the electrode body 120.

In the above, the electric storage elements according to the embodimentand its variations in the present invention have been described, but thepresent invention is not limited to the embodiments and its variations.

That is, it is to be thought that the embodiment and its variationsdisclosed here are illustrative and not restrictive in all respects. Thescope of the present invention is not limited by the above descriptionbut limited only by the terms of the appended claims, and it will beobvious that various changes may be made within the meaning and scopeequivalent to the appended claims. In addition, an embodiment configuredby arbitrarily combining the above embodiment and variations is alsoincluded in the scope of the present invention.

For example, according to the above embodiment, the bottom spacer 170has the first part 171, and the second part 172 thinner than the firstpart 171. Instead, the bottom spacer 170 may have the first part 171,and the second part 172 lower in hardness than the first part 171.Furthermore, the bottom spacer 170 may have only the first part 171without having the second part 172. In these configuration also, thebottom spacer 170 can support the electrode body 120 while toleratingthe expansion of the electrode body 120.

The preset invention can be applied to the electric storage element inwhich the spacer can be smoothly inserted into the case, while thespacer can be prevented from being shifted in position in the case.

What is claimed is:
 1. An electric storage element, comprising: anelectrode body including a positive electrode and a negative electrode,the electrode body including a coated region, which includes activematerials applied to surfaces of the positive electrode and the negativeelectrode, and a non-coated region not including the active material onthe surface of the positive electrode or the negative electrode; a caseincluding a case body for housing the electrode body and a lid platethat covers an opening of the case body, the case body including abottom wall having a long side and a short side, the case body furtherincluding a side wall standing on the short side of the bottom wall, thelid plate being formed with an electrode terminal; an insulating memberarranged in the case to insulate the electrode body from the case; and aside spacer arranged in the case between an inner surface of the sidewall and the non-coated region of the electrode body, the side spacercomprising a resin, wherein the insulating member includes asheet-shaped member that covers the side spacer and the electrode body.2. The electric storage element according to claim 1, further comprisingan electrode collector that includes a conductive member electricallyconnected to the non-coated region of the electrode body, wherein theside spacer is arranged between the electrode collector and the innersurface of the side wall.
 3. The electric storage element according toclaim 2, wherein, in a direction parallel to the long side of the bottomwall, the coated region of the electrode body, the electrode collector,and the side spacer are arranged in this order.
 4. The electric storageelement according to claim 2, wherein the side spacer extends along theelectrode collector in a direction in which the side wall extends. 5.The electric storage element according to claim 1, wherein theinsulating member is bonded or welded to the side spacer.
 6. Theelectric storage element according to claim 1, further comprising anelectrode collector that includes a conductive member electricallyconnected to the non-coated region of the electrode body, wherein theside spacer extends along the electrode collector in a longitudinaldirection of an extension of the side wall.
 7. The electric storageelement according to claim 1, wherein the side spacer includes aU-shaped structure comprising a first portion, a second portionlongitudinally extending parallel to the first portion, and a thirdportion connecting the first portion to the second portion andlongitudinally extending in a direction different from a direction oflongitudinal extension of the first portion and the second portion. 8.The electric storage element according to claim 1, wherein the sidespacer includes a U-shaped structure comprising a first portion, asecond portion longitudinally extending parallel to the first portion,and a third portion connecting the first portion to the second portionand longitudinally extending in a direction perpendicular to a directionof longitudinal extension of the first portion and the second portion.9. The electric storage element according to claim 1, wherein the sidespacer includes a groove longitudinally extending perpendicular to adirection in which the short side of the bottom wall extends and to adirection in which the long side of the bottom wall extends.
 10. Theelectric storage element according to claim 9, wherein the groove of theside spacer is defined by a first portion extending in a width directionof an extension of the electrode body and second and third portionsconnected by the first portion, the second and third portions extendingperpendicular to the width direction of the extension of the electrodebody.
 11. An electric storage element, comprising: an electrode bodyincluding a positive electrode and a negative electrode; a caseincluding a case body for housing the electrode body and a lid platethat covers an opening of the case body, the case body including abottom wall having a long side and a short side, the case body furtherincluding a side wall standing on the short side of the bottom wall, thelid plate being formed with an electrode terminal; an insulating memberarranged in the case to insulate the electrode body from the case; and aside spacer arranged in the case between an inner surface of the sidewall and the electrode body, wherein the insulating member covers theside spacer and the electrode body.
 12. The electric storage elementaccording to claim 11, wherein the insulating member includes asheet-shaped member that covers the side spacer and the electrode body.13. The electric storage element according to claim 12, wherein theelectrode body includes a coated region, which includes active materialsapplied to surfaces of the positive electrode and the negativeelectrode, and a non-coated region not including the active material onthe surface of the positive electrode or the negative electrode.
 14. Theelectric storage element according to claim 13, further comprising anelectrode collector that includes a conductive member electricallyconnected to the non-coated region of the electrode body, wherein theside spacer is arranged between the electrode collector and the innersurface of the side wall.
 15. The electric storage element according toclaim 14, wherein, in a direction parallel to the long side of thebottom wall, the coated region of the electrode body, the electrodecollector, and the side spacer are arranged in this order.
 16. Theelectric storage element according to claim 13, further comprising anelectrode collector that includes a conductive member electricallyconnected to the non-coated region of the electrode body, wherein theside spacer extends along the electrode collector in a longitudinaldirection of an extension of the side wall.
 17. An electric storageelement, comprising: an electrode body including a positive electrodeand a negative electrode; a case including a case body for housing theelectrode body and a lid plate that covers an opening of the case body,the lid plate being formed with an electrode terminal; an insulatingmember arranged in the case to insulate the electrode body from thecase; and a side spacer arranged in the case between an inner surface ofa side wall of the case body and the electrode body, wherein theinsulating member covers the spacer and the electrode body, wherein thespacer is arranged between the insulating member and the electrode body,and wherein the side spacer comprises a first portion, a second portionlongitudinally extending parallel to the first portion, and a thirdportion connecting the first portion to the second portion andlongitudinally extending in a direction different from a direction oflongitudinal extension of the first portion and the second portion. 18.The electric storage element according to claim 17, wherein the firstportion, the second portion, and the third portion define a U-shapedstructure of the side spacer, and wherein the third portionlongitudinally extends perpendicular to the direction of longitudinalextension of the first portion and the second portion.
 19. The electricstorage element according to claim 18, wherein the electrode bodyincludes a coated region, which includes active materials applied tosurfaces of the positive electrode and the negative electrode, and anon-coated region not including the active material on the surface ofthe positive electrode or the negative electrode.
 20. The electricstorage element according to claim 19, further comprising an electrodecollector that includes a conductive member electrically connected tothe non-coated region of the electrode body, wherein the side spacer isarranged between the electrode collector and the inner surface of theside wall, and wherein the side spacer extends along the electrodecollector in a longitudinal direction of an extension of the side wall.